This invention relates to a cabinet for housing telephone equipment, and more particularly to a novel network interface cabinet for use in bringing a large number of pairs of telephone lines into a subscriber's premises, and for accomplishing an interface between the subscriber's equipment and telephone company equipment.
Telephone operating companies have recently been installing interface devices at subscriber premises to provide a separation or demarcation between the operating company equipment and the subscriber-owned equipment on the subscriber's premises. This arrangement proves particularly helpful in providing a manner in which the subscriber equipment may be selectively connected to, and disconnected from, the telephone company equipment, to thereby determine whether any problem or malfunction which may occur is due to subscriber equipment malfunction or telephone company equipment malfunction. Heretofore, such installations have typically been at single-family residences, thus requiring, typically, only termination of and interfacing between perhaps one or two line pairs. In this regard, each independently accessed telephone or "listed number" generally requires one line pair.
Accordingly, at premises having a large number of subscribers such as apartment complexes, office buildings and the like, considerably more complex equipment is required to provide the same sort of interfacing between company equipment and subscriber equipment. Typically, such premises may contain several hundred independently accessed telephone lines and thus require interfacing between a correspondingly large number of line pairs. Thus, an interface facility for such an installation must include termination and protection for the subscriber's telephone equipment as well as proper distribution from the central office cable pairs entering the premises to the subscriber equipment. In this regard, by protection for subscriber equipment is meant the provision of suitable overvoltage and/or "surge arrester"-type protection for each line pair on the premises.
It is further desirable that such large pair count installations be in fully enclosed cabinets, and that access to such cabinets be strictly controlled. That is, while it is desirable that the telephone operating company have access to all of the equipment for purposes of interconnection, repair and/or diagnostic work, it is also desirable that subscriber access be limited to subscriber-owned equipment only. That is, the subscriber should not have access to the telephone company equipment, cables, etc. on the premises, which are terminated in the cabinet. Accordingly, the interior of the cabinet should preferably be divided in such a way that separate access doors or panels can be provided, each having a suitable locking means for limiting access thereto only to the telephone company, or also permitting access to the subscriber, as desired for each portion of the equipment so segregated or divided within the cabinet.
It is further desirable that such a large pair count network interface system provide for a desired number of line pairs to be accommodated in a modular fashion. That is, it is desirable that one or more easily insertable and removable, and also lockable, modular panels be accepted in the cabinet, each panel providing the protection, distribution and termination facilities for a predetermined large number of subscribers. Such a modular arrangement allows a given installation to be expanded as necessary to accommodate increasing numbers of subscribers on the premises.